Time for them to clean up their own nation, sounds like.
They could MMGFTFT...Make Mexico Great for the First Time
Speaking as an American who lived in Mexico for twenty years: Migration from Mexico has been the safety valve for corrupt administrations that have shipped money to Swiss banks and done nothing for their people. The very best thing that could happen to Mexico is to return these educated young people to their mother country to effect change. They have seen what is possible in a country with a vibrant economy and a democratic process and they will not tolerate a Mexico as it is today...there will be revolution.
Now they can turn Mexico into a country where the citizens have a much better way of life, then the Mexico their parents left.
The reality is that most, not all, vote liberal, treat America like Mexico (or fill in the blank with your favorite sh*thole like Somalia etc.) and have just as much, if not more allegiance, to Mexico and being Mexican. They do not subscribe, like most liberals don't, to border,language,culture and American sovereignty under our Constituion. In fact they abuse our system and hide behind our liberties as non Americans. Being American is not a right to the world. It's sickening.